IFNG and nasopharyngeal carcinoma: In Hoechst 33342/PI double staining assay, there were higher percentages of bright blue cells (apoptosis) in NPC cells infected with Ad-IFNγ than those with Ad-LacZ (CNE-2, 25.2% vs 4.8%, p<0.01; C666-1, 19.5% vs 3.0%, p<0.01) (Figure 3B).